Commit 86ef1dfc authored by Tudor Ambarus's avatar Tudor Ambarus Committed by Herbert Xu
Browse files

crypto: atmel-aes - Fix IV handling when req->nbytes < ivsize 



commit 394a9e04 ("crypto: cfb - add missing 'chunksize' property")
adds a test vector where the input length is smaller than the IV length
(the second test vector). This revealed a NULL pointer dereference in
the atmel-aes driver, that is caused by passing an incorrect offset in
scatterwalk_map_and_copy() when atmel_aes_complete() is called.

Do not save the IV in req->info of ablkcipher_request (or equivalently
req->iv of skcipher_request) when req->nbytes < ivsize, because the IV
will not be further used.

While touching the code, modify the type of ivsize from int to
unsigned int, to comply with the return type of
crypto_ablkcipher_ivsize().

Fixes: 91308019 ("crypto: atmel-aes - properly set IV after {en,de}crypt")
Cc: <stable@vger.kernel.org>
Signed-off-by: default avatarTudor Ambarus <tudor.ambarus@microchip.com>
Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
parent 83053677

drivers/crypto/atmel-aes.c

+30 −23
Original line number Diff line number Diff line
@@ -490,37 +490,42 @@ static inline bool atmel_aes_is_encrypt(const struct atmel_aes_dev *dd) 
static void atmel_aes_authenc_complete(struct atmel_aes_dev *dd, int err);

#endif



static inline int atmel_aes_complete(struct atmel_aes_dev *dd, int err)

static void atmel_aes_set_iv_as_last_ciphertext_block(struct atmel_aes_dev *dd)

{

#ifdef CONFIG_CRYPTO_DEV_ATMEL_AUTHENC

	if (dd->ctx->is_aead)

		atmel_aes_authenc_complete(dd, err);

#endif



	clk_disable(dd->iclk);

	dd->flags &= ~AES_FLAGS_BUSY;



	if (!dd->ctx->is_aead) {

		struct ablkcipher_request *req =

			ablkcipher_request_cast(dd->areq);

	struct ablkcipher_request *req = ablkcipher_request_cast(dd->areq);

	struct atmel_aes_reqctx *rctx = ablkcipher_request_ctx(req);

		struct crypto_ablkcipher *ablkcipher =

			crypto_ablkcipher_reqtfm(req);

		int ivsize = crypto_ablkcipher_ivsize(ablkcipher);

	struct crypto_ablkcipher *ablkcipher = crypto_ablkcipher_reqtfm(req);

	unsigned int ivsize = crypto_ablkcipher_ivsize(ablkcipher);



	if (req->nbytes < ivsize)

		return;



	if (rctx->mode & AES_FLAGS_ENCRYPT) {

		scatterwalk_map_and_copy(req->info, req->dst,

					 req->nbytes - ivsize, ivsize, 0);

	} else {

			if (req->src == req->dst) {

		if (req->src == req->dst)

			memcpy(req->info, rctx->lastc, ivsize);

			} else {

		else

			scatterwalk_map_and_copy(req->info, req->src,

					req->nbytes - ivsize, ivsize, 0);

			}

						 req->nbytes - ivsize,

						 ivsize, 0);

	}

}



static inline int atmel_aes_complete(struct atmel_aes_dev *dd, int err)

{

#ifdef CONFIG_CRYPTO_DEV_ATMEL_AUTHENC

	if (dd->ctx->is_aead)

		atmel_aes_authenc_complete(dd, err);

#endif



	clk_disable(dd->iclk);

	dd->flags &= ~AES_FLAGS_BUSY;



	if (!dd->ctx->is_aead)

		atmel_aes_set_iv_as_last_ciphertext_block(dd);



	if (dd->is_async)

		dd->areq->complete(dd->areq, err);
@@ -1125,10 +1130,12 @@ static int atmel_aes_crypt(struct ablkcipher_request *req, unsigned long mode) 
	rctx->mode = mode;



	if (!(mode & AES_FLAGS_ENCRYPT) && (req->src == req->dst)) {

		int ivsize = crypto_ablkcipher_ivsize(ablkcipher);

		unsigned int ivsize = crypto_ablkcipher_ivsize(ablkcipher);



		if (req->nbytes >= ivsize)

			scatterwalk_map_and_copy(rctx->lastc, req->src,

			(req->nbytes - ivsize), ivsize, 0);

						 req->nbytes - ivsize,

						 ivsize, 0);

	}



	return atmel_aes_handle_queue(dd, &req->base);

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